Risk is an inherent part of life when you’re running an oilfield. But usually, field development is all about avoiding or mitigating risks – putting stringent safety measures in place, filtering out unknowns through data and study.
Rarely do you hear an operator say, “We need to pursue more risk as part of our strategy.”
And yet embracing risk is often what you need to do to survive – at least when a field enters its later stages of life and existing wells yield less and less.
In this case, we mean investigating alternative targets – targets that might have been ruled out earlier in the field’s life cycle for being too small, too economically challenging or inaccessible, but which are now the best way to keep productivity up as the field ages.
But how do you know when it’s time to start evaluating these alternative targets?
It’s not as if you can wait until your current wells start running dry and switch to new targets – not when evaluating the viability of targets, acquiring equipment and then drilling new wells could take years. And when daily standby costs can run upwards of $1 million, no operator wants to find themselves saying, “If only we’d started doing this three years ago”.
The question we need to ask first: what’s the goal of late life cycle well planning?
If you said it’s to find new targets for extracting oil from a field, that’s part of it. But most of all, well planning for an aging field is about arresting decline and trying to keep an asset’s production as high as possible for as long as possible.
But therein lies the rub. When you first began developing a field, you had every possible target on the table. That meant productivity was about targeting the simplest parts of a reservoir – the ones that could yield the most oil for the least amount of time, resources and headaches.
Compare that with how a field looks late in its life. Once all of the relatively simple targets have been tapped, the remaining targets are by necessity smaller, often less accessible and more economically challenging to explore.
Mature fields usually need a more complex, creative well drilling approach
Perhaps the remaining targets are ones that were dismissed earlier in the field’s life because they weren’t easily accessible from the surface – but now that you have existing wells in the field, can you drill sidetracks or multilaterals to link them to the new targets? When you’re trying to squeeze the most productivity out of an aging field, linking multiple targets is usually the way to get the most out of the ground without wasting resources on the way down.
This complexity is part of why you need to be looking at your plans for alternative targets and wells long before it’s time to start drilling.
Late field well planning isn’t as easy as looking at the potential targets you identified early on. You need time to evaluate those options again and consider what you need to best extract the oil within – and you don’t want to start that process once production has already started declining.
You might need to design a new decision-making process altogether
When we work with operators to review their well planning, we often see one decision making process in place, tailored for one kind of well.
That one process might work fine for the kinds of targets you pursue early in the field’s life, but when you get to the later stages of the life cycle you might find it doesn’t speak to the longer lead times that come with alternative targets.
Alternatively, you might find your usual decision process is too long. Late in a field’s life, you sometimes need to be completing smaller holes in a few weeks rather than larger wells over several months, and a process designed for the latter can be too cumbersome.
Obviously no one wants to chop parts out of the decision-making process and compromise on safety, but assurance and agility are not opposites. And you don’t want to over-stress your teams by sticking to a rigid process that isn’t fit for purpose.
The answer is to look critically at whether your decision process is really designed for the kind of alternative wells you’re drilling at this stage and, if not, draw up a new process that is.
At Rockflow, our consultants can give expert guidance here, drawing on decades of technical mastery. We can prepare subsurface and wells teams for the switching to alternative targets – taking them through the complete process from hopper generation to post-well review, examining the various well technology options available for the project, and helping them shape a decision-making process for the late life targets coming on the horizon.
